The present invention relates generally to the communication of packet data in a radio communication system, such as a CDMA2000 cellular communication system. More particularly, the present invention relates to a method, and an associated apparatus, by which to communicate packet, and other, data between a mobile station and network infrastructure upon a radio air interface formed therebetween. Operation of an embodiment of the present invention provides a dedicated, reverse-link channel which functionally connects the mobile station to the network infrastructure in a manner analogous to a hardwired connection of a computer in a LAN (local area network).
Advancements in digital telephony techniques have permitted the development, implementation, and widespread usage of multi-user communication systems. Use of a digital communication system in which digital techniques are utilized is advantageous, inter alia, as the communication capacity of a digital communication system is typically greater than the capacity of a corresponding analog system. Error correction of signals transmitted during operation of such a system can also be improved.
A cellular communication system is exemplary of a communication system which has been made possible as a result of such advancements. A cellular communication system permits communications to be effectuated with a mobile station by way of a radio channel, thereby obviating the need for a wireline connection to form a communication channel between a sending and a receiving station. Through use of a cellular communication system, effectuation of communications is possible at locations at which the use of fixed or hard-wired connections would be inconvenient or impractical, such as in a motor vehicle. Cellular communication systems have been implemented using various communication schemes. A CDMA (Code-Division, Multiple-Access) cellular communication system is an exemplary communication system, implemented utilizing code-division techniques.
Some cellular communication systems provide for the transmission of packet data to and from a mobile station. Information which is to be transmitted is formatted into discrete packets of data, and, once formatted, the packets are transmitted upon a communication channel. In a CDMA communication scheme, for instance, a packet channel is assigned by allocating a code, by which the packets of data are encoded. Once encoded, the packets are transmitted by a transmitting station. And, once received at a receiving station, the packets of data are decoded.
While a circuit-switched channel can be formed upon which to effectuate communication of the packet data between the mobile station and the network infrastructure, such allocation would obviate a significant advantage of packet data communications. That is to say, when information to be communicated is formatted into packets of data, a shared channel can be utilized. Information to be communicated pursuant to more than one data service, or pursuant to more than one sending and receiving station pair, can share a single communication channel. Because of the shared nature of communication transmission upon a shared channel, rather than a circuit-switched channel, the communication capacity of communications in a radio communication system can be increased. Conventionally, packet data applications have been carried out on dedicated radio channels, such as to effectuate SMS (short message service) communications in, for example, a GSM (Global System for Mobile communications) communication system or in an active state pursuant to which a mobile state is operable in a CDMA2000 system.
Also, when such a channel is allocated and deployed, significant amounts of build-up and tear-down overhead is required for its effectuation. Therefore, in addition to the communication capacity limitations associated with the allocation of a circuit-switched channel to communicate the packet data, the increased overhead associated with the deployment of the circuit-switched channel is also disadvantageous.
Increased processing capabilities have permitted the implementation of new types of data services to be effectuated, such as multi-media services in which more than one communication-type, e.g., both voice and non-voice information, is communicated. Communication of the more than one data service also presents unique problems requiring resolution when the data services are to be effectuated by way of a radio link.
A manner by which to more efficiently communicate packet data to effectuate one or more data services in a radio communication system would therefore be advantageous.
It is in light of this background information related to communications in a radio communication system that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides a method, and an associated apparatus, by which to better effectuate communications between a mobile station and the network infrastructure of a radio communication system, such as a cellular communication system.
When data is to be communicated by the mobile station to the network infrastructure, a dedicated, reverse link channel is allocated for the transmission of such packet data. The dedicated channel becomes always-assigned to the mobile station, thereby to provide a manner by which to rapidly complete effectuation of the communication of the packet data in a highly reliable manner. The dedicated reverse link channel functionally connects the mobile station to the network infrastructure in a manner analogous to the hardwired connection of a computer in a local area network.
In one aspect of the present invention, a physical layer is provided which includes a forward flow channel and the always-assigned reverse flow channel. The forward flow channel is a broadcast, forward link channel upon which both paging system and also control messages are broadcast in a point-to-multipoint manner. The always-assigned reverse flow channel is used upon which to transmit packet data as well as for the transmission of pilot signals which carry registration messages, and control messages. By defining such channels, a mobile station is, in effect, in constant contact with the network infrastructure.
Because of the always-assigned nature of the reverse flow channel, and the data and messages transmitted thereon, such data and messages are further utilized by the network infrastructure for purposes of locational positioning of the mobile station, even when the mobile station is not otherwise operated in an active call state.
In another aspect of the present invention, a new mobile station architecture is provided. In addition to the improvements to a physical layer which includes the aforementioned forward and reverse flow channels, a packet data layer (PDL) is provided. The PDL is layered between the physical layer and an IP (Internet Protocol) layer operable in a conventional manner, to form datagrams, formed of both header and payload information. The PDL is operable to break the datagrams into smaller units for transmission over the air interface upon the reverse flow channel. The IP layer runs directly on top of the PDL, which in turn runs on top of the physical layer, such as a CDMA2000 physical layer.
In another aspect of the present invention, multi-tasking coordination is provided. That is to say, a multi-tasking entity is provided which examines each active, or recently active, data service of a mobile station-network infrastructure connection. Responsive to such examination, channel allocation is provided to ensure effectuation of the data services in an efficient manner. The common forward channel is defined upon which system-loading, cost information, and mobile station-specific, instantaneous allocation of resource information is broadcast.
In yet another aspect of the present invention, a layering scheme is provided which separates instantaneous network routing and channel resource information from data services while also allowing the data services to function to their requested levels of performance. Data bearers are thereby separated from their associated applications.
In a further aspect of the present invention, a manner is provided by which to better optimize use of the IS-95B data burst and active state packet data available in the proposed CDMA2000 system. User QOS (Quality of Service) requirements and system radio communication capacity is better maximized. Short data bursts are permitted when the mobile station is operated in an intermediate state in addition to the active and dormant states. A determination is made of the length of a user data burst or transaction, the delay which is tolerated by the application, and the error or failure rate tolerated by the application. Responsive to such determination, a manner by which to transmit the data is provided.
Thereby, through operation of various embodiments of the present invention, packet data is communicated from a mobile station to network infrastructure of a radio communication system in a more efficient manner.
In these and other aspects, therefore, a method and an associated apparatus is provided in a radio communication system by which to communicate packet data at a mobile station to network infrastructure of the radio communication system. The mobile station is registered with the network infrastructure at least when the mobile station is initially positioned in a selected registration zone defined in the radio communication system. Responsive to the registration, a dedicated multi-purpose reverse link channel is assigned upon which at least to communicate packet data at the mobile station to the network infrastructure.